Investigating the Relationship Between Material Property Axes and Strain Orientations in Cebus ...

146 Pages·2014·3.11 MB·English

by  Christine M. Dzialo

UUnniivveerrssiittyy ooff MMaassssaacchhuusseettttss AAmmhheerrsstt
SScchhoollaarrWWoorrkkss@@UUMMaassss AAmmhheerrsstt
Masters Theses 1911 - February 2014
2012
IInnvveessttiiggaattiinngg tthhee RReellaattiioonnsshhiipp BBeettwweeeenn MMaatteerriiaall PPrrooppeerrttyy AAxxeess
aanndd SSttrraaiinn OOrriieennttaattiioonnss iinn CCeebbuuss AAppeellllaa CCrraanniiaa
Christine M. Dzialo
University of Massachusetts Amherst
Follow this and additional works at: https://scholarworks.umass.edu/theses
Part of the Biological and Physical Anthropology Commons, and the Biomechanical Engineering
Commons
Dzialo, Christine M., "Investigating the Relationship Between Material Property Axes and Strain
Orientations in Cebus Apella Crania" (2012). Masters Theses 1911 - February 2014. 904.
Retrieved from https://scholarworks.umass.edu/theses/904
This thesis is brought to you for free and open access by ScholarWorks@UMass Amherst. It has been accepted for
inclusion in Masters Theses 1911 - February 2014 by an authorized administrator of ScholarWorks@UMass
Amherst. For more information, please contact [email protected].
INVESTIGATING THE RELATIONSHIP BETWEEN MATERIAL PROPERTY
AXES AND STRAIN ORIENTATIONS IN CEBUS APELLA CRANIA

A Thesis Presented

by

CHRISTINE MARY DZIALO

Submitted to the Graduate School of the
University of Massachusetts Amherst in partial fulfillment
of the requirements for the degree of

MASTER OF SCIENCE IN MECHANICAL ENGINEERING

September 2012

Department of Mechanical and Industrial Engineering
© Copyright by Christine Mary Dzialo 2012
All Rights Reserved
INVESTIGATING THE RELATIONSHIP BETWEEN MATERIAL PROPERTY
AXES AND STRAIN ORIENTATIONS IN CEBUS APELLA CRANIA

A Thesis Presented
by
CHRISTINE MARY DZIALO

Approved as to style and content by:

____________________________________
Ian Grosse, Chair

____________________________________
Robert Hyers, Member

____________________________________
David Strait, Member

__________________________________________
Donald Fisher, Department Head
Department of Mechanical and Industrial
Engineering
ACKNOWLEDGMENTS
I would first like to thank my advisor Professor Ian Grosse for giving me the
opportunity to come to UMASS as a fully funded Masters student. Although being a
Teaching Assistant was a great experience, I would like to thank him again for hiring me
as a Graduate Research Assistant in my second year at UMASS and sparing me from
further teaching duties. I am grateful for his continuous support, advice, and patience
while introducing me to the world of Finite Element Analysis. I would also like to thank
Professor David Strait (University at Albany) and Professor Robert Hyers for serving on
my committee and for their outside knowledge of materials and paleoanthropology, not to
mention the hours they spent editing this document.
I would like to extend my appreciation to all those involved in the BIOMESH
2011 Workshop. Dr. Betsy Dumont, Dr. Julian Davis, and Dan Pulaski thank you for
your assistance with deciphering CT anatomy, modeling related questions, and error
messages. In addition, I would like to thank my collaborators on the Hominid Project
(supported by the National Science Foundation). Many thanks to Dr. Callum Ross and
everyone at the University of Chicago (Jose Iriarte-Diaz and Laura Porro) for hosting me
over the summer and letting me into your world of in vivo strain collections and IGOR
code. Finally, a huge shout out goes to Paul Dechow (Baylor College of Dentistry) and
Andrea Taylor (Duke University) for your contributions of muscle PCSA measurements,
material property data, and guidance. Without your time consuming efforts the specimen
specific model of Curly would not exist.
iv
I would like to thank my lab mates and fellow graduate students: Sarah Wood,
Briana Tomboulian, Mike Berthaume, Jay Breindel, Andrew LaPre, Krishna Samavedam,
Lieselle Trinidad, Lu Huang, Jeff McPherson, Vivek Premkumar, and Sameer Jade:
without you guys, I'd be lost.
Last but certainly not least, I would like to thank my family and friends for their
endless support and encouragement.

v
ABSTRACT

INVESTIGATING THE RELATIONSHIP BETWEEN MATERIAL PROPERTY
AXES AND STRAIN ORIENTATIONS IN CEBUS APELLA CRANIA

September 2012
CHRISTINE MARY DZIALO, B.S., SMITH COLLEGE
M.S.M.E., UNIVERSITY OF MASSACHUSETTS AMHERST
Directed by: Professor Ian Grosse
In this research we used probabilistic finite element analysis to determine whether there
is a statistically significant relationship between maximum principal strain orientations
and orthotropic material stiffness orientations in a primate cranium during mastication.
Before carrying out the probabilistic finite element analysis, we sought to validate our
cranium finite element model. This validation involved sampling in-vivo strain and in-
vivo muscle activation data during specimen mastication, the collection of specimen-
specific post-mortem data of physiological cross sectional area of masticatory muscles,
and post-mortem measurement of orthotropic material properties of the cranium. We used
various geometric-modeling permutations of a previously constructed finite element
model of the cranium of a tufted capuchin monkey (Cebus apella) individual called
Curly. Curly‟s in vivo bone strains and electromyography signals were obtained at the
University of Chicago as the individual masticated hard food items. At Baylor College of
Dentistry post-mortem in vitro experiments were carried out to gather orthotropic
vi
material property values for Curly, and at Duke University post-mortem in vitro
experiments provided Curly‟s PCSA values of its masticating muscles. A comparison of
in vivo and finite element predicted (i.e. in silico) strains was performed to establish the
realism of the FEM model. To the best of our knowledge, this thesis presents the world‟s
only complete in-vivo coupled with in-vitro validation data set of a primate cranium
FEM. In general, reasonably good agreement was obtained at most of the strain sampling
locations. Thus, our results indicate that a validated FEM of a Cebus apella cranium was
achieved. This gives collaborating anthropologists, biologists, and engineers the
confidence that these models have sufficient accuracy to address the research questions
pertaining to cranial structure morphology.
Probabilistic finite element analysis design was then utilized to determine the dependence
of maximum principal strain orientations on material stiffness orientations in particular
craniofacial regions during mastication. It was discovered that the relationship between
material stiffness and maximum principal strain orientations is more localized and does
not have a consistent global trend. This suggests that the maximum principal strain
orientations are more dependent on loading conditions and/or the shape of and location in
the cranium rather than the material stiffness orientation of a particular region. It was
also uncovered that the material stiffness orientations are not developed in a way that is
optimal for feeding biomechanics from the perspective of minimization of total elastic
strain energy. Therefore, a more thorough examination of biting/chewing situations is
needed to fully understand the co-evolution of bone morphology and material properties
in the facial skeleton. Results from this research will provide insights into the co-
evolution of bone morphology and material properties in the facial skeleton.
vii
TABLE OF CONTENTS
Page
ACKNOWLEDGMENTS ................................................................................................. iv
ABSTRACT ....................................................................................................................... vi
LIST OF TABLES ...............................................................................................................x
LIST OF FIGURES .......................................................................................................... xii
CHAPTER
1. INTRODUCTION ...................................................................................................1
2. RESEARCH OBJECTIVE ....................................................................................15
3. MATERIALS AND METHODS ...........................................................................17
3.1 Research Approach ..........................................................................................17
3.2 Study 1 .............................................................................................................23
3.3 Study 2 .............................................................................................................38
4. RESULTS: STUDY 1 ............................................................................................58
4.1 Isotropic Validation .........................................................................................58
4.2 Orthotropic Validation .....................................................................................68
5. RESULTS: STUDY 2 ...........................................................................................73
5.1 Block Example .................................................................................................73
5.2 Probabilistic Design .........................................................................................76
5.3 Design Optimization ........................................................................................82
viii
6. DISCUSSION & CONCLUSIONS .......................................................................85
6.1 Study 1 .............................................................................................................85
6.2 Study 2 .............................................................................................................88
6.3 Conclusions ......................................................................................................90
APPENDICES
A. DOCUMENTATION ............................................................................................92
B. CUSTOM WRITTEN CODE ..............................................................................100
C. DATA AND INPUT FILES ................................................................................110
D. RESULTS ............................................................................................................118
WORKS CITED ..............................................................................................................127

ix